Changing the FX fork on an fxst to an FL fork

[Julio]

Julio,
That's a cool picture.  As a side bar, how did you get the lines into the picture?
Signed: Computer challenged

You can draw lines with any decent graphic program. I use Corell Paint Shop Pro PhotoX2.

Back on subject.
I found a lot of info and a rake and trail calculator on the RB Racing website.
Scroll to the bottom of the page for the calculator.
It even has an input for triple tree rake and a list of BT models with raked trees and by how many °s.
The FXST is not on that list.

[rageglide]

rageglide,
Certainly don't want to do it if it won't work.  That's why I'm asking.  If it will clear and work properly, I'd like to get the fork tubes behind the neck.  Do you know for sure if an FL bagger type tree will clear the tank on the '90 fxst frame?  TIA

I can't imagine any FL bagger tree would work.  The bagger frame is totally different with the neck pushed forward.  Trees' for the bagger are basically the same since the 80's.

You could certainly try it and see, sorry, I'm not trying to squash creativity even if it sounds that way.  With regard to clearance, all i know is that the fork tins on an FLST front end come extremely close to the five gallon tanks so there's not much room to spare.  I think you'd need to go to a custom tank to find room if you moved the tubes back. 

I'll try and throw an incline-o-meter on the WG tonight or tomorrow but I am almost positive the WG tree has 3 degrees.  Hey, Julio may be right, and I may be wrong!
Interestingly the top bracket is the same on shovel wide glides since 1980, all FXST/C Softails and the evo DynaWG.. Only the tree changed for the Dyna, the other Trees are the same with minor mods. 

[Evo160K]

Thanks all.

[Homeward Bound]

When you say "FL fork" do you mean FL as in FL softail, e.g. a Fatboy, or FL as in FLH touring?

FLHs have 20 7/8" long tubes, FXSTC's 24 1/4"  (P/N: 45417-84 - same as 84/99 FXST, FXDWG etc) but both are 41.2 mm or 1 5/8 diameter.

I think FL softails have shorter front ends, and less rake so that might what you are after ... but don't necessary need it.

I suspect the FLH backward triple trees have nothing to do with your experiences and it's more about a having a tighter, twin disk front end and more rubber on the road. If anything the old FLH triple trees are a disadvantage, because the top one lack any pinch bolts (this has finally been changed on the latest models).

There are plenty of FXSTs with 16" front wheels and twin disks floating around, although I think an 18" would also work well and, to my taste, look better. You don't need quite the load rating of tyres as an FLH does and so sticking with 18" would be a good compromise. Using FLH lowers, e.g. going to twin calipers and a 1" axle wheel would make more sense to me. They are available very cheaply and twin disks will balance braking loads without twisting forks better.

Alternatively, if you want to keep experimentation cheap & simple just to see if it was the size that mattered, go with Fat Boy wheels and fender (Single disk only, without a little work. You would just need to change the spacer to a narrow one. Try wheel bearing spacer 40910-84b and a 0.250" wheel spacer hub cap). That would let you work out if it was just the amount of rubber you were riding that made the difference.

Lowering the front is fine if you lower the rear to keep angles the same but, depending on tires, it would not be a lot. Like 3/4". If that and twin discs does not fix it alone, I would then try burlier triple trees to tighten up your front end. I'd guess your front end was twisting under braking and just not laying down enough rubber.

Do you like spokes or alloys?

You could just re-lace your present hub with a 16", 17" or 18" rim and see how it rolls.

Read up on "rake and trail" to understand why you don't want FLH trees.

[rageglide]

Homeward, is that an OEM fatboy fender??   Did you shim it to fit?  Maybe the TC era FX front end is same boss to boss as the FL.  Evo's aren't.  I had an aftermarket "Fatboy" fender on my '86 FX, installed in early '88, before the HD built a Fatboy.  The aftermarket fender hugged the tire very close. 

Good lookin bike too!

[Evo160K]

Homeward Bound,
My wheels are spokes.  Handling is not an issue here, it's fine.  Braking hard without having the FX front end tend to flop to the side is what I'd like to get away from  With hard braking the FLH front end tends to stay centered.  The concern is will the flh triple trees on an fx softail frame hit the tanks.  I think Rageglide is correct in what he says.

I like your bike.

[rageglide]

Evo you can put dual disks on the your scooter.  Install the FLH (bagger) lowers on your fork tubes.  It's gonna require fiddling.  There are kits from CC or Drag that will allow you to keep your existing single piston but on both sides. 

BUT.  Later style have bigger axle so your choice is an adapter axle, or changing to a later wheel/bearing assembly(not sure about this).  NFW will the bagger tree work on a softail frame without huge mods (cut/weld, etc).  Pitch those bagger trees, thats my advice.

I've never had any issues with the braking pull from one side. Not saying it doesn't do it.  I've always been able to lock up that front wheel with a single brake, not ideal... But it is nice to have a little balance.  So I totally understand your goal.

[Evo160K]

Rageglide,
Good thinking!  As it happened, I converted the bike to dual discs maybe 20 years ago (it's a 1990 fxst).  A company back then was welding caliper mounting lugs to the right slider like you see in the picture.  Also converted to the 5/8" master cylinder.  No complaint with how well the bike brakes, it's fine.  All of that did take some "fiddling" as you said. The concern is the tendency for the stock, oem, fx camber wheel to flop while braking versus the flh caster wheel which tries to center itself.  I didn't realize what a huge difference that is until I had to do a full on panic stop recently with a Street Glide (flhx without abs))........truly remarkable.

[attachment removed after 60 days by system]

[Homeward Bound]

Sounds like you might have other problems then ... e.g. both calipers are not working equally. Has one side's piston stuck?

Try making sure everything is A-OK first, then pick up another wheel off Ebay/Craigs, or a hub and lace it to a smaller diameter.  Let us know how it goes.

Upgrading to FLH lowers and, especially, the Brembos would still give you a great improvement.

[rageglide]

Leaving the stock FX trees on and lacing up a 16" will still have that same 'floppy' feeling.  Actually worse imo.  While I liked the stability and durability of the 16" wheel on my old FXSTC, I always felt the combo was a bit twitchy.   The FLST front end with 16" wheel feels much more planted at the cost of a bit of responsiveness.

[Evo160K]

Thanks one and all.  I appreciate your thoughts.  Before I go any farther, I need to determine if the FLH triple trees will clear my tank.  On first look, it doesn't appear they will.

[Homeward Bound]

Thanks one and all.  I appreciate your thoughts.  Before I go any farther, I need to determine if the FLH triple trees will clear my tank.  On first look, it doesn't appear they will.

You've really got stuck on this idea and it's a non-starter. It's not the issue and it's not the solution and, no, they won't work. Your frame has a different rake.

You'd be making a mistake to go to the obsolete design of triple trees the FLH's use (no top pinch bolts) and which are designed to be hidden by fairings or nacelles.

If you really must, you need to speak to a good frame builder ... preferably one that makes or sell proper billet triple trees ... but you headed into work you won't want, e.g. cutting and re-raking your frame's headstock.

Just try a 16" wheel first ... you can always sell again afterwards if it does work.